0515 GMT - The 10-year U.S. Treasury yield is trading at "historically significant" levels, Siebert Financial's Mark Malek says in a note. Against this backdrop, consumers are becoming considerably more pessimistic, he says. "The bond market and consumers may be detecting economic stress earlier than equities," the CIO says. The 10-year Treasury yield is down 1.4 basis points to 5.278%, having hit 5.310% overnight, its highest level since May 2002.